Willow driers



G. FLESSNER WILLOW DRIERS ug. 3U, 19150 2 Sheets-Sheet 1 Filed Sept. 24,1956 ,mn/. M MM, w

ug. 3U, 1960 G. FLEISSNER 2,950,540

WILLOW DRIERS me@ sept. 24, 195s 2 sheets-sheet 2 mmh BY 6M# WM ma@ATTORNEYS WILLW DRIERS Gerold Fleissner, Egelsbach, near Frankfurt,Main, Germany, assigner to Fleissner & Sohn Maschinenfabrik, Egelsbach,near Frankfurt, Main, Germany, a rm of Germany Filed Sept. 24, 1956,Ser. No. 611,658

Claims priority, application Germany Sept. 28, 1955 Claims. (Cl. 34115)The present invention relates to'new improvements in willow or sievedrum driers for drying loose brous material.

ln driers of this type such as were known prior to this invention, thebrous material or ber bat was usually moved along a revolving sieve drumby being coiled partly over and partly under the upper and lower halvesof the drums, respectively. Such movement of the material along thelower halves of the drums required considerable force in the form ofsuction merely for the purpose of holding the material attached to thedrum Surface. Therefore, since the suction required for the dryingoperation was also used for retaining the brous material on the lowerdrum surfaces, it was unavoidable that tufts of bers dropped off thesesurfaces.

In order to be able to utilize the suction current entirely for thedrying operation and to prevent ber tufts from dropping o the drums, theattempt has already been made to rdry the loose brous material merely onthe upper sides of a series of perforated drums which are disposedadjacent each other and all rotate in the same direction. However, incarrying out such method, diiculties have been encountered intransferring the bat of loose brous material from one drum to the uppersurface of the other. The bat was only partly picked up from theprevious drum or it rolled together between the adjacent drums so thatthe following drum could only receive a part of it. Consequently, thematerial was likewise conveyed over the drums unevenly and could alsonot be dried uniformly.

It is therefore the principal object of the present invention to conveythe bat of loose fibrous material uniformly along the upper surfaces ofa series of perforated drums and to prevent the material from stickingto the individual drums, from being rolled up between adjacent drums, orfrom partly dropping off the drums.

A feature of the invention for attaining this object consists inproviding a plurality of adjacent perforated drums which are rotated inthe same direction and over the upper sides of which the bat of brousmaterial is passed, and mounting a hollow perforated roller intermediateeach pair of adjacent drums so as to rest and roll preferably under itsown weight on the upper surface of the bat, so that the latter will becontinuously in contact with and guided by the surfaces of either thesurfaces of the drums or those of the intermediate rollers.

An additional advantage attained by the invention is the fact that thedrying chamber in which the perforated suction drums are mounted may beof much lower height than required previously in previous driers of thistype. This is due to the fact that heating elements are only requiredinthe upper portion of the drying chamber. This advantage may be furtherutilized according to the invention by providing two or more rows ofdrums underneath each other so that the eiciency of the entire drierwill at least be doubled and the outer dimensions thereof beconsiderably reduced.

nited States Patent Further objects, features, and advantages of thepresent invention will be apparent from the following detaileddescription which is to be read with reference to the accompanyingdiagrammatical drawings, in which- Fig. l shows a willow drier accordingto the invention with a single row of perforated drums;

Fig. 2 shows a similar drier with two rows of perforated drumssuperimposed upon each other;

v Fig. 3 shows a detail view of a portion of two adjacent drums with theintermediate perforated roller, illustrat- Y ing its action upon the batof bers; and

t suction fans.

Fig. 4 is a cross-sectional view through Fig. 2 and showing the suctionthrough the bat and drums.

Referring to the drawings, and rst particularly to Figs. l and 3, thenew drier consists of a housing 10 in which a plurality of perforateddrums 11, 12, 13, and 14 are rotatably mounted. A pair of conveyor belts15 and 16 conduct the bat 20 of loose fibrous material toward and awayfrom the drums and the drier. Hollow perforated rollers 17, 18, and 19are interposed between the adjacent drums 11, 12, 13, and 14,respectively, and rest with their own weight on the bat 20 and therespective adjacent drums. Cover plates 21, 22, 23, and 24 are providedin the customary manner at the inside of the drums so as to cover upthose parts ofthe drums from the inside thereof which are not covered onthe outside by the ber bat 20. Thus, as shown in Fig. 3, the bat 20 runsover that part of drum 11 which is not covered on the inside by thecover plate 21, and it is attached thereto due to the suction of the Theupper end of cover plate 21 is disposed relative to the perforatedroller 17 so that there will be no suction upon bat 20 intermediate thetwo ldrums 11 and 12 so that the bat will then be released from drum 11and be picked up by or follow the perforated roller 17 because of thefan suction which then again canv exert its action. The same procedureis repeated at the perforated rollers 18 and 19 until the ber bat 20 isnally taken olf the surface of drum 14 by the 'conveyor belt 16.

In this movement of ber bat 20 along the surface of drums 11, 12, 13,and 14, the perforated rollers 17, 18, and 19 also rotate, being drivenmerely by the friction on drums 11 to 14 or the ber bat Z0,respectively. These rollers also pull the ber bat slightly apartwithout, however, changing the thickness or width thereof on the drums.Since rollers 17, 18, and 19 are perforated, they do not obstruct thefree passage of air to the ber bat.

Although the frictional engagement of rollers 17, 18, and 19 on the batis usually suicient to rotate the same, they may, if desired, also bepositively driven by any suitable driving mechanism.

Since a willow drier of a type according to the invention may beenclosed within a very low housing 10, it is also possible to providetwo rows of such perforated drums underneath each other and to pass theber bat rst over one row of drums, for example, the lower row, andthereafter over the other.

Such embodiment of the invention is diagrammatically illustrated in Fig.2, in which -two rows of `drums 11 to 14 and 25 to 2S are mountedunderneath each other, and la perforated roller is mounted between eachpair of adjacent drums. The ber bat 26 is inserted into the drier on thelower conveyor belt 15 and runs over the upper sides of `drums 11, 12,13, and 14, whereupon it is passed from drum 14 over drum 25 of theupper row and then successively over the other upper drums 26, 27, and28, and nally out of the ldrier on the upper conveyor belt 16. The airthen flows through the drums in a downward direction, as directed bybaffles 29, 30, 31 and 32, and -is drawn off the lower drums in theaxial j l l 2,950,540

direction thereof. Motors MY rotate the drums, and, if Y" desired, therollers by means of the gearing and shafting shown :in Figs. 1, 2 and 4,and at the same time drive the suction fans 35V which communicate withthe interiors of thevr drums Vfor'v drawing anair current through therollers, bat and drums for drying the hat.V

Fig. 3 -finally-shows on an enlarged scale the gap inter-V mediatetwofadjae'ent' drums whichis iilledout by the perforated'roller'17. Sucharrangement of the drums saves considerable Vspace permitting even alarger number of drums to be mountedY Within the smallest possiblespace, thus increasing thedrying eliiciency of theY drier and 'keepingthe cost of production and Yoperation thereof at the lowest 'possiblelevel.

' While the invention has beendescribed in detail and Having thusdescribed my invention, wha-tl claim as new is: v Y

1.7A willow drier `for drying a bat of loose fibrous materialvcomprising a plurality of perforated drums mounted Yadjacent each otherin the same plane, means for rotating said drums in the same directionand for passing said bat along the upper sidesof said drums,` a

perforatedrroller rotatably mounted above and intermediate each pair ofadjacent drums and adapted `to actY VSame plane, means for rotating saiddrums in the same direction and for passing said bat along the uppersides of said drums, a perforated roller rotatably mounted aboveand inthe yV-shaped gap intermediate'each pair of adjacent drums and adaptedto rest under its own weight on the upper surface of said bat, baiesarranged on vthe lower sides and inside of the said perforated drums andending adjacent to therlines of contact befv tween said rollers andsaidfbat, and suction means communicating with the interiors ofmsaiddrums yfor drawing an airfcurrent through said rollers, said bat, andsaid drums for drying said bat.

3. A willow drier for drying a bat of loose iibrous material comprisinga plurality of perforated drums mounted in a row closely adjacent eachVother inthe same plane, meanst'for rotating said drums in the samedirection and for passing said bat along the upper sides of said drums,a perforatedV roller rotatably mounted above and in the V-shaped gapintermediate each pair of adjacent drums and adapted to rest under itsown weight on the upper surface of said bat, batiies-arranged on thelower sides andinside of the said perforated Y 'drums and'endin'g in thedrumsv in advance of said rollers above the lines 'of contact betweenthe said rollers `and said bat and rearwardly of said rollersrunder thelines of contact between the said rollers and said bat, and suctionmeans communicating withV the interiors of said drums lfor drawing anair'current through said rollers,

said bat,-and said drums for drying said bat.

4. A willow drier Lfor drying abat of Vloose Iibrous material comprisinga plurality of perforated drums mounted in at least -two superimposedrows and closely Y adjacent each other in the same plane in eachrespective row, means for rotating said drums in one row in onedirection and those in the superimposed row in the opposite direction,V-a perforated roller mounted above and in the V-shaped gap intermediateeach pair of adjacent drums Ain eachrow and adapted to act upon theupper surfaceV of said bat, baffles arranged on -t'he lower sides and-inside of the said perforated drums and ending adjacent to the Ilinesof contact between the said rollers and said bat, and suction meanscommunicating with the interiorsqof said drums for drawing an airYcurrent through said rollers, said bat, and said drums for drying saidbat. Y j v Y5. A willow drier as defined in claim 1, further comprisingmeans for positively driving said perforated rollers at a peripheralspeed substantially in accordance with the peripheral speed of saiddrums.

References Cited in the tile of this patent UNITED STATES PATENTS1,377,793 Schwartz May 10, 1921 1,601,332 Whitehead et al Sept. 28, 1926FOREIGN PATENTS Great Britain May 14, 1925

